


Curiosity of Modern Society

by Osomatsu



Category: Touhou Project, おそ松さん | Osomatsu-san (Anime)
Genre: Crack Crossover, F/M, Fake/Pretend Relationship
Language: English
Status: In-Progress
Published: 2019-10-15
Updated: 2019-10-17
Packaged: 2020-12-16 19:30:10
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 4,400
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21041561
Author URL: https://archiveofourown.org/users/Osomatsu/pseuds/Osomatsu
Summary: When Reimu is dropped into the middle of modern Japan in a place known as Akatsuka Ward, she finds herself in the company of six brothers as she tries to solve the latest incident. But this incident may be a bit more difficult than those of the past for many reasons, and everyone can only hope for the best...from the worst.





	1. Let's Go To The Mall!

It wasn't that often he went out to the mall. It was every now and then, but that was more Totty's bag. More often than not, he was happy to just stick to the horse tracks, or the pachinko parlors, or anywhere else...but there he was that day. Not sure what took him, honestly. Osomatsu scratched under his nose, looking around at the crowd. He puffed out a small sigh, a frown crossing his face. There were so many people here. Ichi would've had an anxiety attack at the sheer thought of it, he imagined. Oso was more adaptable, but even he was feeling a bit overwhelmed. He folded his arms behind his head, looking around.

  
Clothing store. Clothing store. Clothing store. Good /lord./ Wait. He froze. Women's underwear store. /Not bad./ He pressed his face to the glass, staring at the pictures of girls in underwear, smirking to himself. But halfway through this, he realized that was...pretty pathetic, honestly. He couldn't talk to a girl so much to the point that he was staring at underwear models and sizing them up in the middle of a crowded mall. Wow. That was sad, even for him. He shook his head, and moved forwards, only to see what looked like...that was a pretty big commotion.

  
Something was going on. Something /weird./ And he was naturally curious. Whereas most people would probably run the other direction, Osomatsu walked forwards. Whereas most people would probably declare that a very firm and prompt 'fuck this shit, I'm out' kind of situation, Osomatsu was more than glad to keep going.

  
This was quite possibly because he was a moron, but still.

  
He walked into the store - a department store - and towards the source of the chaos. There, in the middle of the store was a girl. A girl...who looked like she was in some kind of cosplay. He raised a brow. Was this some kind of performance? But she looked thrown off. Frightened, even. And she was launching some kind of...pellets at anyone who got close. He stepped forwards, only for the girl to catch on, and for him to barely dodge in the middle, barely grazing through the mess with sheer luck. A pellet scraped the outside of his hoodie, and he grimaced. That...actually felt like an actual bullet. "--Hey, hey! Wait!" He spoke up, choking some words out while a few other people took to hiding. "Uh! Lady, it's--it's fine. I'm not going to hurt you! Can you not, err...fire off dangerous bullets in the middle of a store? I'm...here to help?" What was he getting himself involved in?

  
The typical nonsense, probably. His phone buzzed in his pocket, and he ignored it. Probably unwise. Backup would've probably been a good idea, but no one ever accused Osomatsu Matsuno of being intelligent. The woman in front of him, standing on top of a table with folded shirts on both sides from where she was standing was probably about his age - early 20s, if he had to estimate, with black hair, and probably one of the strangest outfits he’d seen in a long time, with a big red bow on top of her head, long black hair, and a red dress, with no sleeves, yet some kind of white sleeve-like things on her arms lower down. If he had to guess, she looked vaguely like a...miko? But she looked at him with a cold, appraising stare. He almost flinched, but the girl stepped down. “You’re going to help me?” She asked, her hands on her hips.

  
“I can try?” Osomatsu asked, mildly regretting the situation he’d put himself in. The girl seemed to size him up, before sighing.

  
“Alright. First question. What human village is this?” Human village? What? “And why...is this store so odd-looking?” She was asking all of this with a straight face, like nothing she was saying was odd in the least. Osomatsu almost faltered, but then he responded.

  
“Uh, you’re in Akatsuka Ward. As for the store...most up-their-own-ass clothing stores look like this nowadays.” Osomatsu shrugged, trying not to question the girl’s lines of thought too hard. “Now I get to ask some questions. What’s your name, and...what was with those bullet things?”

  
The girl frowned, but let out a small sigh. “Hakurei Reimu. Shrine maiden of the Hakurei shrine and yokai exterminator. I’m not supposed to be here, to be frank. I’m never supposed to leave Gensokyo, really, much less for some human village I’ve never heard of in all my years…” She pinched her forehead. “...Have you seen a woman around here in a purple dress? Sometimes holds an umbrella, able to spawn little gaps with eyes peering out at you from them, has this smug bitchy smile that shows that she’s intent on ruining your day?”

  
“Uh...no?” Osomatsu shook his head. This was...a lot. Yokai exterminator. So this lady was here - Reimu was here - telling him that she was some kind of weird miko who beat up mythological creatures? She really didn’t explain the bullet things, either, but it seemed like there was a lot on her mind…

  
Which got worse when he saw security showing up. “Hey, you there! Was it you and your girlfriend causing some kind of commotion here?!”

  
“Ah. Shit.” That was worth swearing over, but Reimu simply looked unamused. “Officer, there’s a perfectly reasonable explanation for this…”

  
“Sure there is. And you can explain at the station.” The officer seemed pissed off already, which only got a growl out of Reimu. Osomatsu was almost ready to bust into a cold sweat.

  
“I suggest you leave us be.” Reimu stated. “I’m going to leave this store, and I’m going to leave the city. If you value your life, human, you shouldn’t interfere.”

  
Oh, this was bad. Osomatsu looked from the increasingly annoyed officer to Reimu, back and forth until Reimu...began lifting off of the ground?

  
“You can fly?!”

  
Reimu barely cast him a glance as she raised into the air. Osomatsu glanced behind him at the increasing number of officers, then swallowed. Reimu looked like she was ready to bolt. “Wait! Take me with you! Please! You need a guide to the human world here, I’m your guy! I’ll--I’ll help you find this lady!” He...really didn’t know how to explain any of this, nor did he want to become the subject of any police procedure, so--...at least the shrine maiden paused, looked at him, and let out a small ‘tch’ noise.

  
“How troublesome. But I suppose assistance might be nice.” Before he knew it, she’d picked him up, slinging him over her shoulder. He let out a little yelp...and that was before she began flying at a rapid speed, resulting in him pretty much unable to do anything but scream. “Shut up! You’re fine!”

  
“I’m in the air, I’m going fast, and I’m pretty sure I just got a bug inbetween my teeth!”

  
“That sounds like a personal problem to me!!!” She snarled, before landing somewhere on a side-street, putting him down. “There.” Reimu landed on the ground herself, blowing a bit of hair out of her face. Osomatsu was still beyond confused. Honestly, if this were any other situation, he could see himself pretty much immediately hitting on this girl - not that that wasn’t a constant with most girls, but Reimu was pretty much a solid 9/10 - but the magic stuff and the personality? Yeah, there were issues there. Not to mention the fact she seemed perpetually pissed off. So. This was a fine mess he’d gotten himself into. “Human.” Probably the worst in a long time. “Oi. Human.” He really should’ve called one of his brothers, at least--

  
“Idiot human!” Reimu was staring him down again, causing him to blink out of his concerned trance. “Good grief. You have the worst braindead stare.” This chick really didn’t mince words, did she? “Where do I get a drink around this area?”

  
...Well, now she was speaking his language. Osomatsu looked around, slightly smiling, scratching under his nose. “That...is something I know the answer to. C’mon, there’s a bar this way.” He motioned with his head. Reimu followed along. “...Wait, do you have any money?”

  
“No.” Reimu replied, looking around, her arms folded behind her head as she walked. The streets were far from empty, and there were people occasionally giving her stares due to her odd clothing, but Reimu discarded their opinions. They didn’t matter, anyway.

  
“Then how are--” Osomatsu paused, then sighed. “...You want me to pay, huh?”

  
Reimu smirked, just a tad. “I did just save you from what appeared to be the authorities. You’re in debt.”

  
“They were only pissed off at me because you set them off!” Osomatsu protested. Reimu waved it off.

  
“Semantics. Besides. I’m a woman of a holy shrine, donating sake cleanses your sins. Or something.”

  
“Or something.”

  
“Yes.” Reimu’s smirk stretched across her face. “Either way, we both know you’ll give in. No use hiding it. So, ah, thank you. In advance.” She looked around, her smirk slipping a bit. “...This looks nothing like the human villages I’m used to.”

  
Osomatsu sighed. Who did this girl think she was? But he did raise a brow slightly, slowing down a bit in his walk to walk side-by-side with her. “Are you familiar with mostly country villages?”

  
“I suppose.”

  
“...What did you mean by yokai extermination, by the way? And those bullet things?” Osomatsu asked. “You didn’t really explain any of that.”

  
“I’m not sure if you’d understand. Or believe me.”

“Try me.” Osomatsu replied almost immediately.

Reimu heaved out a sigh as she walked. “My home is a land called Gensokyo. There, I act as the primary peacekeeper between yokai. The ‘bullet things’--” She made air quotes with her hands. “--are known as danmaku. They’re a non-lethal system of dealing with conflict. Well. Non-lethal for Gensokyo residents.”

“Ah. So you really could’ve killed me.”

“I mean, I still can.” Reimu smirked. Osomatsu snorted. “...” Her face formed into an intensely contemplative one, however. “I don’t know why I’m here, though. I’m...not supposed to leave Gensokyo, and my only theory is that this is the work of some yokai. The only one powerful enough to displace me is Yukari...”

“Is that the lady you mentioned you were looking for?”

“Mmm. She’s a bitchy old hag who can use gaps to gap people through reality.”

Osomatsu blinked. “So you mean like...” He motioned his hands in a spreading motion, then mimed getting inside it. “...Like that?”

“Mhm.” Reimu nodded. “She looks a lot less dumb doing it though, but then again, you /are/ a human...”

“Oi, oi! I’m the one who’s helping you the most here.” Osomatsu pouted childishly. Reimu snickered. “...What’s the need for you to get back so badly, anyway?”

“I’m also the maintainer of the barrier between Gensokyo and the mortal world.” Reimu explained. “...If I’m not there, the barrier may weaken and even break. And then I wouldn’t be able to stop the yokai from doing what they please.”

“Yeesh. They’ve gotta be big monsters, don’t they?”

“Actually,” Reimu shrugged, “they look like cute girls.”

Osomatsu froze. “...All of them?”

“Most of them.”

Osomatsu’s face firmed up into a smirk that pretty much said his intentions immediately. “Then damn, I’d /let ‘em/ do what they please.”

Reimu stared at him dryly. “They’d eat you. They would literally think you were the dumbest prey to ever exist, and they would devour you whole. And that’s not a pleasant way to go.” Osomatsu’s smirk dropped into a pout again, Reimu simply shaking her head. They kept walking until Osomatsu saw the tell-tale lights of the bar he was familiar with ahead.

“There it is!”

“Oh, thank-whatever-God-I’m-supposed-to-worship.” Reimu mumbled, walking ahead. Osomatsu couldn’t help but look amused again, watching her for a few seconds as he stood in place.

“You’re a /miko/ and you don’t know what god you worship.”

“Nope.” Reimu shook her head, looking back. “It’s not like they have many followers anyway. I’m broke. I never get any donations.”

“Surely some people give you, like, pity donations.”

“Ah, sometimes.” Reimu seemed to shrug it off. “Then I spend the money on sake and other ways to amuse myself.”

Osomatsu paused again, bursting into laughter. “Pff--hahaha, wow. What the hell kind of a miko are you?”

“One of a kind.” Reimu replied, not missing a beat. “Now, come, human. You said you were buying.”


	2. Fictionality of Fake Relationshipping

The bar wasn’t deserted, despite it being the afternoon. There were a few people - no one that Osomatsu seemed to know, at least so far as he saw. Reimu immediately stepped over to the bar. “Oi. Two sakes. And don’t you dare water ‘em down, I can tell the difference.” This was probably a good time to examine his situation mentally. He was in a bar - he was in a bar paying for drinks for some kind of superpowered shrine maiden who could fly and shoot magic bullets (or ‘danmaku’, whatever), and he’d promised to help her hunt down this ‘Yukari’ woman who had the power over controlling gaps.

There was no normal way to examine this situation. There just /wasn’t/. He’d have liked to say there was, but there wasn’t exactly a book called ‘So You Just Met A Hot Girl With Superpowers...’

He paid for the drinks, and sat down across from her at a table, watching in mild awe as she threw back half her drink in one gulp. “...Huh. Most girls I know can’t throw back drinks half that well. I’m impressed.” Honestly? If she wasn’t trapped in this mystical bullshit, Reimu was very much the definition of ‘the ideal woman’. Feisty, hot, and knew how to throw back her alcohol. The problem was that she confused him at every turn...

And she’d probably threaten to rip off his dick if he even tried. He could imagine that response even without saying anything.

“I didn’t ask for your approval, human.” Right. There was a wry tone to her voice, however, to show that she knew she was being obstinate.

“Can’t you at least call me by my name? Osomatsu. Oooh-soooh-maaah-tsuuuu. It’s not that hard to say.” Reimu seemed to think this over, then took a more restrained sip of her drink.

“You haven’t earned it yet. /Human./” Reimu drummed her fingers against the table.

“I have to earn it?! How?”

“Dunno.” Reimu grinned. “Figure it out yourself.” Osomatsu huffed, though the curve of his mouth threatened to turn up in a smirk himself. “So. I suppose we should think of a plan of discovering Yukari...” She sighed. “...I’ll have to find locations where magic seems particularly strong. And if I’ve been displaced, there very well could be others. I may have to fight them to get them in a sound state of mind.”

“Yeesh. Well. I’m just your hyooooomaaan tour guide.” Osomatsu droned a bit, elongating ‘human’ to emphasize the slight degrading nature of only being referred to by...very common species.

“Mmm. My idiot.” Reimu nodded.

“Never mind, human works.”

“Thought so.” Reimu sighed. “I’ll have to find--” She pursed her lips. “...Human. You have designated yourself my guide. Therefore, your contact with me in this unfamiliar land must remain constant.” Osomatsu had drifted back into his thoughts, pulling out his cellphone and checking to see if anyone had texted him.

“Therefore, I shall be lodging with you.”

Osomatsu nearly dropped his phone, juggling it in his hands for a second after hearing that, mumbling ‘shit, shit, shit, shit!’ before regaining his grasp on it and looking at the unamused Reimu. “Uh. Reimu-chan. That may not be the best idea.” Reimu’s expression shifted into confusion and interest.

“And why not?” She asked. “You promised. You’ll be my guide. It’s only natural for me to stay with you. Or do you want there to be an innocent woman on the streets?” Reimu went on, the obvious guilt-slinging not getting past him for a moment.

“I can pay for, like, a hotel room or something for you to stay in!” Osomatsu offered. “I just, um, don’t think staying with me is the best idea. You’d hate it. Pretty sure you would.”

“You still haven’t said /why./”

“Because I--I don’t live by myself. I live with my parents. And my brothers. And what do you think they’ll think when they see me bring in a girl?”

“That you’re offering charity on an innocent, kind woman of faith that deserves only the best treatment.” Reimu replied, a bit smugly. “You’ll surely go to heaven, then.”

Osomatsu stared for a few seconds, before sighing. “I’m...not sure if you’re fucking with me or if you’re being entirely sincere right now with this whole egocentricism thing.”

“How about both?” Reimu finished her drink, still as smug as ever. “I don’t see a problem. Really.”

“Yeah, you don’t right now. Because you don’t know them like I do.” Osomatsu pinched the bridge of his forehead. Reimu waved her hand dismissively. “Alright, fine. But remember. You brought this upon yourself.”

“Oh, woe is me, I have to put up with a few more humans.” Reimu’s tone was more amused than anything. “I’ll be fine. I’ll just have to start calling you Humans One through Six.” Osomatsu couldn’t help but feel internally amused by the fact that Reimu had absolutely no idea what she was signing on for. “I’m capable, Human One. Or did you forget my job for years has been taking care of yokai?”

“You haven’t dealt with many human men, huh?” Osomatsu scratched under his nose while Reimu frowned.

“Should I consider myself fortuitous?”

“Well...” Osomatsu trailed off, taking a sip of his own drink as he seemed to think over his words. “...I’m gonna lay it out to ya straight, Reimu-chan. You’re really pretty. And mortal men?They’re weak. My brothers are the worst kinds. Desperate. Virgins.”

Reimu tapped her chin, then grinned mischievously. “Ah. So all mortal men are so taken with my appearance that I’d have devotees? How horrible, you’re right, Human One.” She hummed. “...You’re talking about this like you’re not a virgin. Is that true?”

“....Well...”

“Aha.” Reimu seemed to have a revelation. “So you’re just as taken with me as any other mortal man, and on top of that, you’re also a virgin. You’re becoming more and more transparent to me, Human One. Remember that I am a woman of the cloth, however. I cannot desecrate myself to some random mortal male.”

“I--that’s not...” Osomatsu wasn’t able to fully deny it. Reimu noted this, and started laughing.

“Sooooo sorry, Human Oneeeee. But hey. We can keep this between us.” Reimu winked. “And just so you don’t get jealous...that applies to everyone. Not just you. At any rate...I’m flattered.”

“I didn’t say I was--”

“You didn’t say you weren’t.” Reimu cut him off at the pass, and Osomatsu huffed just a tad as Reimu leaned back, smugly. “You should get me another round because you like me so much.” She made a kissy face, as he rolled his eyes, getting up to go do exactly that, followed by her smiling faux-sweetly. “Thank you~”

“Yeah, yeah.”

“It was a genuine sign of appreciation.”

“A smug one.”

“...Yes, and?”

It was a while before they were walking home, both having gotten a decent enough buzz - but, Osomatsu noted to himself, not enough to be stupid drunk. They had to be coherent for this next bit. Which was walking inside his home. “I’m hoooooome~” He peeked into the living room. Sure enough, his brothers were there, up to their usual activities. “So, guys. I, um. Have someone to introduce you all to.” His brothers all stared up at him, and Osomatsu took a breath in. “It’s complicated as to why they’re here, but the long and short of it is that...they don’t have anywhere else to go and I kind of maybe made a promise.”

Reimu nonchalantly walked in, looking around. The minute they noticed the girl in the room, all of their jaws seemed to drop in unison. Choromatsu in particular looked completely shell-shocked. Reimu raised a hand. “Hi. My name is Hakurei Reimu. Shrine maiden and yokai exterminator by trade. Human One over there is my guide to this mortal realm, therefore I am his guest. And I suppose by extension all of you are as well.”

The first to recover was Jyushimatsu. “Nice to meet you, Reimu-chan!!!” He zipped over, taking her hand and shaking it wildly. Reimu blinked, a bit surprised. Choromatsu swallowed, before hopping up, mumbling a quiet ‘excuse me’, and dragging his brother into another room.

“Okay. What’s with the Touhou cosplayer?” Choromatsu flatly asked, motioning back to the other room. “She’s gorgeous and her cosplay is on point, as is her character, but--”

“What’s a Toohoo?” Osomatsu asked. Choromatsu stared at him blankly.

“It’s--” “I found her at the mall.” Osomatsu began to explain. “She was alone. She was freaking out and shooting these bullet things everywhere. I told her I’d help her if she stopped, so she did. She can fly as well as shoot those pellet-y bullet-y things. She said she’s looking for a woman named Yukari.”

Choromatsu’s face twisted in increasing confusion. “Either you’ve gotten wrapped up in the strangest, longest cosplay skit...”

“What the hell are you going on about?” Osomatsu asked. Choromatsu pulled out his phone, Googling the word ‘Touhou’, and Osomatsu watched as several pictures of Reimu and other girls showed up.

“Reimu isn’t real. She’s a video game character.”

Osomatsu stared at the pictures, then swallowed. “I don’t know. She seems pretty real to me. She genuinely can fly and all that stuff.”

“That’s what I don’t understand.” Choromatsu mumbled. “She’s the genuine article. But that genuine article isn’t supposed to exist. I know weird things happen around us all the time, but this--this is weird, even for me.”

“...” Osomatsu hissed through his teeth. “I don’t know. Shit. Do you think that Dekapan would have any idea? He’s the expert we consult on most weird science-y crap.”

“Maybe? We can go see soon.” Choromatsu nodded, putting his phone away. “But in the meantime...”

“Do /not/ let her know she’s fictional.” Osomatsu was firm with that. “She’s--”

“Incredibly violent and hasty. Yeah. I know.” The two brothers nodded to each other, walking back in the other room, only to find--

Oh. Fuck.

“...Ah. Welcome back, my one and only.” Reimu smiled sweetly, walking over to grip onto Osomatsu’s arm - tightly, very tightly, enough that it hurt a bit. “I was just telling kaa-san how it would be so very kind for her to allow us to stay here while you’re earning money for our future together~” She chimed, so sweet and brightly. It was downright /unnatural./

Osomatsu looked over at his mother - who had clearly fallen for it, hook line and sinker, staring at Reimu with absolute adoration. His brothers, however, were clearly in on it, but weren’t saying a word, causing Osomatsu to wonder for a split-second as to what exactly Reimu had said to them while he was talking to Choromatsu. Reimu’s sharp gaze at him, only visible for a moment, clearly meant one thing: play along. So he would.

“Ah--y-yeah, surprise! I’m so glad you don’t mind, kaa-san...”

“Of course I don’t mind! Reimu-chan is such a sweet girl, offering to help where she can just to stay...” Matsuyo cooed. “Unlike some other NEETs I could name.” Her voice grew sharp and stern for a moment, causing the brothers to grimace. “...It will be so nice to have you around, Reimu-chan. Welcome to our family. Now, shall I get started on dinner--?”

“Please. Allow me. You should try to relax when you can, kaa-san.” Reimu’s tone was sickeningly sweet, endearing herself further. “I’ll handle dinner. Along with my dearest Oso-kun, of course...” She dug her fingernails into his arm. Osomatsu resisted the urge to wince a bit.

“So sweet--! I’ll be upstairs, then.”

“I’ll get you when it’s ready.” Reimu replied, and dragged Osomatsu into the kitchen. Immediately when she felt the coast was clear, her smile dropped. “That played out as a far better excuse than the ‘providing for a holy woman’ excuse. I’m going to emphasize now, Human One, that you should only expect this as an excuse for my lodgings and nothing more.” She took out some vegetables, and a knife, briefly pointing the knife at her companion. “Are we clear?”

“I’m aware!!” Osomatsu frowned. “You didn’t have to dig your hand into my arm so hard. Jeez. That kinda hurt.”

“What hurt was the knowledge I’ll have to keep that act up.” Reimu nudged him with her elbow. “Help. We’re working on this together.”

“What are you making?”

“Miso soup.”

“Alright. Fine.” Osomatsu sighed, but started to help. “What made you swap excuses, anyway?”

“Human Six, Human Two, and Human Four assured me that my previous excuse wouldn’t work. Human Five is off in his own little universe.” Reimu shook her head. “Reminds me of a fairy. Not too bright, but full of energy. Less egotistical, more friendly, however, so it seems. What were you and Human Three discussing?”

“We...” Osomatsu bit his lip. “We have a friend who maybe - just maybe - can help us track down magic signals. He’s a bit of a weird guy, but he’s a scientist and he invents some pretty strange stuff for strange uses. If anyone would know how to help, it might be him.”

“I’ve known a lot of weird scientists in my time. It’s worth a shot.” Reimu nodded. “Good plan. I’ll come along.”

“...Also, uh.” Osomatsu looked her up and down. “You’re going to probably stay here for a while. So...we might want to get you updated on a less conspicuous look. Along with a few other culture things.”

“Mm. It’s surprising you all have kappa technology here.”

“...Kappa technology?”

“Mhm.” Reimu nodded. “The TV was invented by Kawashiro Nitori. Who is a kappa.”

“....No. No, it wasn’t.”

“It--” ...Reimu’s frown increased. “...It was where I come from.”

“I think you got ripped off.” Osomatsu snickered. Reimu frowned. “The TV’s been around for a while. Just wait until you learn about some other stuff. We’ll help. Promise.”

“....You better.”


End file.
